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1. Icecream95 (ixn@mastodon.xyz)'s status on Saturday, 18-Feb-2023 12:07:18 JST Icecream95

   Trying to add a feature to Gnome Crosswords, which uses GTK4.

   This experience is making me think that Tk was a well designed GUI toolkit after all...

   Already I've found a use-after-free in the toast code, which is not a good look for libadwaita. But the real question is how long it takes for me to debug it.

   The support for toasts does seem quite badly designed though... or maybe that's just the bug.

   • Adrian Cochrane repeated this.
   • Icecream95 (ixn@mastodon.xyz)'s status on Saturday, 18-Feb-2023 12:49:42 JST Icecream95

     in reply to

     The bug appears when quickly creating and dismissing toasts.

     By compiling a debug build of libadwaita, I get a better backtrace for where the "free" is:

     g_signal_emit_valist -> hide_done_cb -> free_toast_info -> g_free

     Adrian Cochrane repeated this.
   • Icecream95 (ixn@mastodon.xyz)'s status on Saturday, 18-Feb-2023 12:50:57 JST Icecream95

     in reply to

     So perhaps this is happening:

     show_toast() is being called to show a toast, then very soon after hide_current_toast() is called to hide that same toast.

     Occasionally, the hide_done_cb() callback is called *before* show_done_cb(), when usually it should only come after.

     That makes me curious as to how glib iterates through the list of callbacks.

     Adrian Cochrane repeated this.
   • Icecream95 (ixn@mastodon.xyz)'s status on Saturday, 18-Feb-2023 12:59:53 JST Icecream95

     in reply to

     glib uses a linked list of handlers, but...

     The signals are connected from different objects (info->show_animation vs. info->hide_animation), and so it depends on which animation object emits the signal first.